中年及老年患者中，氨甲酰甲胆碱的正性肌力反应与血浆浓度之间的关系。

Relationship between positive inotropic responses and plasma concentrations of xamoterol in middle-aged and elderly patients.

Marlow H F, Hine F L, Snow H M, Pouleur H, Rousseau M F

Medical Research Department, ICI Pharmaceuticals, Alderley Park, Cheshire.

Br J Clin Pharmacol. 1990 May;29(5):511-8. doi: 10.1111/j.1365-2125.1990.tb03673.x.

Abstract

We examined the relationship between the contractile state of the left ventricle and the plasma concentration of xamoterol in patients with ischaemic heart failure. 2. Identical studies were conducted in 14 middle-aged (all male; mean age 51.3 years, range 42-61) and 10 elderly patients (six male, four female; mean age 67.7 years, range 64-72). 3. Patients received seven cumulative doses (0.0005-0.2 mg kg-1) of xamoterol. After each dose the rate of change of pressure in the left ventricle at a developed pressure of 40 mm Hg and normalised for this pressure, (dP/dt)/DP40, and plasma concentrations of xamoterol were measured. 4. There were dose-related increases in (dP/dt)/DP40. Curves relating changes in (dP/dt)/DP40, expressed as a percent of the maximum observed response, to changes in xamoterol plasma concentrations were constructed for the middle-aged and elderly patients. From these curves the mean effective concentration (EC) value to produce a particular response could be calculated. In the sample sizes studied, the difference between the EC values over a range of responses for the middle-aged and elderly patients did not reach statistical significance, indicating that cardiac responsiveness to xamoterol was similar in the two groups of patients. 5. Plasma concentrations of xamoterol over the range of 39 to 150 ng ml-1 produced positive inotropic responses which varied between 70% and 90% of the maximum observed effect of xamoterol.

摘要

我们研究了缺血性心力衰竭患者左心室收缩状态与血浆昔莫洛尔浓度之间的关系。2. 对14名中年患者（均为男性；平均年龄51.3岁，范围42 - 61岁）和10名老年患者（6名男性，4名女性；平均年龄67.7岁，范围64 - 72岁）进行了相同的研究。3. 患者接受了七个累积剂量（0.0005 - 0.2 mg kg⁻¹）的昔莫洛尔。每次给药后，测量左心室在40 mmHg的发育压力下压力的变化率，并针对该压力进行归一化处理，即(dP/dt)/DP40，以及昔莫洛尔的血浆浓度。4. (dP/dt)/DP40与剂量相关增加。为中年和老年患者构建了将(dP/dt)/DP40的变化（表示为最大观察反应的百分比）与昔莫洛尔血浆浓度变化相关的曲线。从这些曲线可以计算出产生特定反应的平均有效浓度（EC）值。在所研究的样本量中，中年和老年患者在一系列反应中的EC值差异未达到统计学显著性，表明两组患者对昔莫洛尔的心脏反应性相似。5. 昔莫洛尔血浆浓度在39至150 ng ml⁻¹范围内产生了正性肌力反应，其变化范围在昔莫洛尔最大观察效应的70%至90%之间。